Synthesis Of Several Antibiotics And Intermediates

The present paper primary task involves the research on several antibiotics and intermediate's synthesis, mainly includes the following works:1. A Novel Synthesis Process of Aminothiazoly LoximateThe present paper designed an efficient synthesis route of Aminothiazoly Loximate. Take acetacetic ester and sodium nitrite as materials, got ethyl 2-(hydroxyimino)-3-oxobutanoate. Then got it react with bromine, obtainstioned ethyl 4-bromo-2-(hydroxyimino)-3-oxobutanoateroute. This compound reacted with thiourea and organic base to yield the new product, which was methylated with dimethyl sulfate and then was hydrolyzed. Subsequently it was mixed with hydrochloric acid to get acidificated. Following five steps, high purity product was obtained with a yield up to 40%. There is only one step need to be tracked with HPLC.2. The Synthesis Research of Ceftiofur SodiumWe study the traditional synthesis methods about Ceftiofur Sodium and propose a new way. The 7-ACA, which is used as meterials, reacts with furan-2-thio1-formic acid in weak base solution. Then the product reacted with AE thioleste to obtain cefiiofur acid and finally was converted to its sodium salt in the same reactor with sodium iso-octoate. Traditional methods were improved greatly. The yield of the last step was increased to 50%. The total yield is up to 34%.3. The Research on Synthesis of Valnemulin HydrochlorideValnemulin Hydrochloride is the new generation of semisynthetic animal-specific antibiotics, which is the derivate of pleuromutilin. It's many properties: broad-spectrum, better antibacterial activity, and fine drug kinetic-characteristics, low-residue, security and so on. The synthesis method contains four steps including the esterification, the thiosulfate reaction, the acylation and the acidification. With high purity, the yield reached 53%. The raw material can be get easily, and the process is reasonable and suitable for industrial production.